JPS59166417A - Teeth of saw and manufacture thereof - Google Patents

Abstract

A saw blade exhibits a foundation (1) of spring steel, which exhibits along one edge projections (3), each separated by a chip space (2), each carrying a seat (4) each for a cutting material plate (6, 6') and each forming a tooth back (5). The cutting material plates (6, 6') exhibit a cutting edge and a true rake (7) and are arranged at an effective rake angle ( gamma ), while each two adjacent cutting material plates (6, 6') form a pitch (t) with the mutual interval of their cutting edges and/or cutting tips. The cutting material plates (6, 6') are attached with varying pitch (t) and with varying effective rake angle ( gamma ).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cutting tool made of particularly spring steel having a plurality of protrusions extending along the edges, each separated by a chip space, providing a seat for each cutting tool material chip and each forming the back surface of the tooth. a plurality of cutting tool material chips having a cutting edge and a rake face and provided at an effective rake angle and fixed by their protrusions, each two adjacent cutting tool material chips (5) A pitch is formed at a distance between opposing cutting edges or cutting edges. Saw teeth of this type can be configured as band saw teeth or hack saw teeth or circular saw teeth, or can also be provided in the form of rotating circular band saw teeth.

A sawtooth of the type mentioned at the outset is known from DE 28 16 428 A1. Cutting tool material tips, in particular in the form of tungsten carbide cutting teeth, are hereby fixed at their projections by hard soldering.

The arrangement of the cutting tool material chips in the basic body should be regular, taking into account the pitch for fixing the cutting tool material chips and the effective scooping distance that forms the cutting tool material chips. A given saw tooth always has the same pitch and the same effective rake angle throughout the tooth range.

This effective rake angle is limited to a range of positive angles in order to achieve sufficient stability of the cutting tool material chips at their protrusions. This type of saw blades, especially circular saw blades, emit significant noise when using them. In order to reduce this noise generation during sawing (6), known saw teeth have a concave side surface on the cutting tool material tip. A regular arrangement of the cutting tool material chips of a matched type and with the same pitch and the same effective rake angle is a favorable precondition for the generation of undesired resonant vibrations. This resonant vibration also causes the cut surface of the workpiece to be streaked, grooved, and uneven. Moreover, this vibration leads to micro-cracks (due to fatigue) in the cutting tool material chips, thus also shortening the service life of this type of saw tooth. Resonant vibrations are the cause of the significant scratching noise that occurs during sawing, and ultimately result in significant stress on the saw, whether it is a band saw or a hacksaw.

Federal Republic of Germany Patent Application No. 2522618 #
A saw blade for bandsaws or hacksaws, in particular for metalworking, is known from the book 1llI. In the manufacture of this type of saw tooth, a strip of high-speed steel is welded in a high vacuum to a basic body made of spring steel. Teeth are milled into this strip and into the basic body. (7) After milling, the teeth are hardened in partial areas of the strip, with the basic body also being hardened in the same way. The working surface of the tooth is then ground to No. 2 and placed. The rake face and back face are also ground. These grinding processes are relatively expensive. This is because the grinding operation as a result of using a wider strip compared to the spring steel basic body is
This can only be done using an intermediate layer. The configuration of the teeth can also be buttoned so that rough cutting edges and finishing cutting edges are formed alternating with each other. It is noteworthy that when constructing such a sawtooth, great significance is also assigned to the floating grinding of the tooth brush 7.

In addition to the expensive production in the intermediate layer, this known saw tooth has a large loss of high-speed steel, which itself is used for milling, although this hard cutting tool material is only required in the region of the tooth tips. It must be removed by machining and grinding. The serrations are again regular and have the same pitch and the same effective (8) rake angle. The configuration as a roughing and finishing cutting edge makes it possible to achieve constantly repeated conditions for the evacuation of workpiece chips with extremely short removal times.

Starting from a basic body made of spring steel, a welded strip made of high-speed steel is machined so that a pitch varying from tooth to tooth is achieved with a constant effective rake angle of the teeth.
Band saw teeth are also already known. In this way, a constant series of different pitches is formed, each from tooth to tooth, and this series is repeated, so that a large number of pinch series are provided one after the other with regular reproduction.

This known saw tooth suffers from the drawback that the required material removal by pinning and grinding increases the force quantitatively and value-wise, especially as the pitch of the teeth increases. This is especially true, for example, when the chip space is enlarged during the production of band saw teeth for relatively large cross sections by subsequent milling or grinding of the respective second already finished tooth. That applies.

(9) The known saw blades mentioned at the beginning, which are provided with cutting tool material tips, especially in the form of cemented carbide, cut even difficult-to-cut materials relatively easily, have a long service life and have a relatively short cutting time. It is advantageous to be able to achieve fine machining. All sawtooths with cemented carbide tips generate a single frequency that can resonate at frequencies in the same situation of the machine/tool/workpiece system, which does not sufficiently influence the reasons for the regularity of chip formation. There is a flaw.

It is therefore an object of the invention to be able to influence the frequency determined by the configuration of the saw blade in the breaking process with the saw blade, and also during sawing, and thus to minimize resonances with frequencies in the same situation in the machine tool workpiece system. This can be prevented by configuring saw teeth of the type mentioned at the beginning.

According to the invention, deburring is achieved by fixing the cutting tool material tip with a varying pinch and a varying effective rake angle. The present invention aims to create conditions as different as possible during the 4ns of sawing in the individual cutting tool material chips, and thus to the same situation in which resonances can mutually occur which are harmful to the chip or have a negative impact on the chip in the breaking process. Starting from the knowledge that certain frequencies should be avoided as much as possible. The pitch largely determines the temporal sequence of the generation of cutting forces during the penetration of the cutting tool material chips into the material to be cut. The effective rake angle essentially influences the magnitude of the cutting force generated, the direction of the cutting force as well as the loading of the connection between the cutting tool material chips of the basic body and their protrusions. The combination of a varying pitch and a varying effective rake angle (although a series of different values is still decisive for certain frequency occurrences in the same situation) is optimal for maximum durability performance. This characteristic of the saw blade according to the invention has been found to be sufficient in order to make a high specific cutting capacity and a maximum cutting area m2 of the band length or plate length in the spirit of the tasks set for the work of the method. This is especially true when cutting difficult-to-cut materials, such as relatively high-fertility materials such as steel, stone, glass (11), composites, etc.; however, due to their low inherent evaporation properties, machines, tools, The same situation in the product chain is also of special importance in the case of large low carbon steels, which are alloys that tend to resonate at AM frequencies. It is interpreted as the distance from the pitch tooth surface to the south face, which distance can be measured or determined, depending on the embodiment, also at different slope points. As long as the cutting edges are arranged perpendicular to the direction of movement of the cutting tool material chips in the cutting gap, a pinch can be measured by nine opposing distances of two sequentially reading cutting edges. If, on the other hand, the cutting edges are arranged at an angle with respect to the direction of movement of the cutting tool material chips, this will result in the formation of tooth tips, in which the lateral projections of the tooth tips of adjacent cutting tool material chips are different from each other. Determine the pitch. The same applies when the cutting tool material chips are configured and provided as roughing and finishing cutting edges.

In this case, too, a pitch series is created, each consisting of successive pitches that are different from each other, and these pitches can be provided in constant reproduction with the saw teeth (12). However, in this case, it is possible to create an extremely large series of pitches, so
Within the limited dimensions of the sawtooth, the association law can no longer be determined. It is important not only to change the pinch, but also to change the effective rake angle in combination with the pitch.

This influences not only the value and direction of the cutting force generated in the silk binding, but also the formation frequency of the cut piece formation over time. In this case, the details can be configured in such a way that series of different effective rake angles are formed, and the number of individually different effective rake angles of the series must not unconditionally correspond to the number of pinches of the pitch series. .

Combinations of varying pitch and/or varying effective rake angles may be provided varying from tooth to tooth. In this way even a simple repetition of the same conditions in the area of two successive teeth or cutting tool material chips is prevented.

In the inventive configuration of the saw tooth, all the advantages already indicated per se can also be utilized if the saw tooth is provided with (1S) cutting tool material chips, which cutting tool material chips are Regardless of the material of the cutting tool, it can be finished completely or humanly, and only then the fixing of the cutting tool material chip takes place on the basic body. The structure of the base body then remains tough and malleable and is no longer negatively influenced by the otherwise necessary hardening process. Since the cutting tool material chips are also machined on all sides by the required uplift grinding, only fixing on their protrusions of the basic body is necessary. This fixing can also be carried out by soldering, welding or gluing; the last mentioned method step can be carried out cold or semi-cold and without affecting the material of the support and of the cutting tool material chip. The pitches varying within the pitch series can have individual pitches (14) that are balanced against each other up to a ratio of 1:2.5. This means that within a pitch series the pitch can vary over a wide range, but also form 2.5 teeth elsewhere in the pitch series within a pitch series consisting of an interval determined by the amount large pitch. This means that it is wide enough to accommodate 2.5 or 2.5 cutting tool material chips. However, such a large range of pitch variation is generally not required.

As a variable effective rake angle, positive and/or negative effective rake angles can be provided within a certain effective rake angle.

If the effective rake angle is varied in the range of positive effective rake angles, saw teeth with high cutting properties are then produced. A negative effective rake angle produces high strength. The extension of the varying effective rake angle over both indicated ranges provides a versatile saw tooth. In order to vary the effective rake angle, when using a cutting tool material chip configured with the same thickness over its length (also when using a constant rake angle β of the cutting tool material tip)
= 0) Since their sheets are tilted differently by the protrusions and are provided with -(15) non-constant angles α, the cutting tool material chips that match and the fixation of different relative positions Different effective rake angles occur even at different times. However, it is also possible to use cutting tool material chips of different shapes or which are at least partially formed differently from one another.

The number of different pitches in the pitch series may correspond to the number of different effective rake angles in a given effective rake angle series. Thus a certain regularity is achieved, but
However, it is advantageous in terms of ease of manufacturability.

Furthermore, this number of pitches and effective rake angles can be chosen relatively large. It is therefore also possible to select a number of different pitches of one pitch series which is greater than the number of different effective rake angles of one effective rake angle series, which again lends itself to simplified manufacturing. A saw tooth is created that can be used for a large range of workpiece sizes. However, the number of different pinches of one pitch series can be less than the number of different effective middle rake angles (16) of one effective rake angle series, so that the sawtooth can be used for division. A relatively stable cutting behavior is generated. The pinch sequence is determined by the width of the milling cutter relative to the projection or chip space.

Cutting tool material chips can be constructed from cemented carbide, high speed steel, ceramic cutting tool materials, and the like. The ceramic cutting tool material can be a single or multilayer cutting tool material, such as Celmet. Cutting tool material tips made of cemented carbide provide a particularly good cutting surface and are also suitable for durable materials that are difficult to cut. If the cutting tool material tip consists of high-speed steel, similar properties are obtained as in the case of a saw tooth with a strip of high-speed steel welded to the basic body, but the material losses during production are significantly lower. In addition, the cutting tool material chips and base bodies made of high-speed steel can each be processed separately and thus optimally depending on the respective requirements.

Eventually, the cutting tool material chip can also be provided with an anti-wear IF coating which is applied before fixing (17) the cutting tool material chip to the basic body.

A method for producing saw teeth of the described type is provided according to the invention in which the basic body is made of a sheet with a varying pitch of projections and a varying slope at those projections, and chips of the same or unequal cutting tool material are formed on them. It is to be fixed to the seat. In particular, therefore, the use of the same cutting tool material chips is preferred insofar as varying pitches and varying effective rake angles are created automatically, so to speak, finishing machining,
9.For example, it requires something like grinding. The protrusions on these protrusions relative to the cutting tool material tip can be created by milling and/or grinding in combination with a press upsetting process to change the effective rake angle. Sharpening of the protrusions is not excluded, although generally sharpening is not necessary and should therefore be avoided. The pressing process produces a cold fixation of the material of the basic body at the fixing point to the cutting tool material chip. At the same time as this fixing, the sheet surface can also be upset relatively widely, so that the cutting tool material chips can be fixed even better on this wide surface in this way. However, it is also possible to fix the cutting tool material chip with a sheet of protrusions and then grind it further. Moreover, such a grinding process can in any case be associated with a finishing process.

Relatively large geometries are then no longer necessary.

Another manufacturing method for saw teeth of the type mentioned at the beginning is that their protrusions on the base body can be made with a regular pitch and the same slope of the sheet, and can also be carried out differently when using the same cutting tool material chips. The grinding process may be carried out or the cutting tool material chips, which are not the same, may be fixed with a sheet.

The invention will now be described in detail with reference to a number of embodiments.

The band saw tooth shown in FIG. 1 has a basic body 1, which is made in particular from malleable spring steel (19). Chip space 2 milled back to the edge of the strip material
projections 3 are formed, which on their front side each form a seat 4 and on their back side a tooth back 5. Each sheet consists of four relatively large, vertically or slopingly arranged and therefore bulge surfaces. The inclination of the strip relative to a plane perpendicular to the longitudinal direction or a slope is the sheet angle α.

Cutting tool material chips 6.6 in each of those sheets 4
' is fixed. The cutting tool material chip 6.6' is
It has a rake angle shown as β. Since cutting tool material chips 6.6' of constant thickness and therefore the same thickness are used over the vertical extension of the chip, β is also =0 = constant. The respective effective rake angle α is determined from γ-α+β, where α-r is taken at each location. Different effective rake angle γ.

. γ2≠γ3・・・γn
-+-f! γ. It is shown as follows. In that case, n is (
20) Number of different effective rake angles in the effective rake angle series. It will be appreciated that a number of similar (or non-similar) effective rake angle series can be implemented in the strip one after the other. Their effective rake angle γ1 is determined by the tooth flank, since, as in the example of diagram K1, a cutting tool material tip 6.6' is used and this tip has equal material thickness over its vertical extension. If 7 extends parallel to each surface of 7-to 4, the sheet angle will be the same as α1. Because there is a problem with the effective rake angle itself or its change.

It is understood that if differently formed cutting tool material chips are used, the sheet angle α in the sheets can also be formed to be exactly consistent or regular. The cutting tool material tip 6' can be configured as shown in FIG. 1, namely as a rough cutting edge (cutting tool material tip 6') and a finishing cutting edge (cutting tool material tip 6). There must absolutely only be two types of cutting tool material chips. Three or more modalities are necessarily conceivable. In FIGS. 1 to 3 (21) cutting tool material chips 6.6' of the same thickness are shown, so the sheet angle α of the sheet 4 is the same as the effective rake angle of the cutting tool material chips. The fixing of the cutting tool material chip 6.6' on the seat 4 of the projection 5 takes place by welding, hard soldering, gluing or the like.

It is important to be able to vary the effective rake angle.

This is done from tooth to tooth or from process to process. In FIG. 1 this is a different large pitch-y-t, ≠1.
Indicated by @1n, -~.

The cutting edges 8, 8' in the illustrated embodiment extend in the saw gap transversely to the direction of advancement of the cutting tool material chip 6.6', so that the pitch from cutting edge 8 to cutting edge 8' is is determined between each two adjacent cutting tool material chips 6.6'. The cutting tool material tip 6 likewise has two tooth tips and the cutting tool material tip 6' has one tooth tip. If the cutting edge 8 and the tooth 8' are provided inclined with respect to the direction of movement, determine the pitch by lateral projection of the cutting edge or tooth tip onto a plane, or measure on this plane (22). This is recommended.

Sawtooth 1. In the band saw blade, multiple series of different pitches and multiple series of different effective rake angles are combined with each other, and the number of pitches of the pitch series is thoroughly matched with the number of effective rake angles of the thread rows. Must not match 2. You can select a match to make it relatively easy.

Since the cutting tool material chips 6,6' are machined with a finish on preferably all surfaces, finishing after fixing with their projections 6 is no longer necessary. The cutting tool material tip 6.6' can also obviously have different dimensions and outer contours than shown with reference to FIG. Since the cutting tool material chips 6.6' in any case project laterally beyond the width of the basic body 10, a lateral flying angle is formed and the sharpening with the defects associated with the flying angle is eliminated. It is understood that it can be done. Similarly, the tip flying angle is maintained.

Figure 2 shows a fragment from a circular saw tooth.

In this case too, the pitch changes and the effect changes (2S) The rake angle is being assembled.

In FIG. 3 a further embodiment of the invention is shown with reference to a band saw tooth, for example in which cutting tool material tips 6.6' configured as roughing and finishing cutting edges are used;
Since the chips are constructed with equal thickness over their longitudinal extension, the front side of the chips, ie the tooth flank 7, extends parallel to their back surface. Therefore, the effective rake angle β-0 of this cutting Aft I dissimilar material chip is. Since the seat 4 is milled and/or upset differently, different seat angles α also occur at the individual projections 6.

This results in different effective rake angles corresponding to the respective sheet angles α. This is because β-0. Needless to say, in this case as well, the pitch t is not constant, but varies. The advantage of this embodiment is that it uses only the cutting tool material chips 6,6' or even a single type of cutting tool material chips and nevertheless achieves different effective rake angles (24) for different pitches. It is in.

Another embodiment of the band saw blade is shown in FIG. In case B, when the pitch changes, a constant sheet angle is used, which can be, for example, 90°. The cutting tool material tip 6.6', t' has a rake angle that differs from zero and is not constant. In this way it is also possible to achieve a varying effective rake angle that is proportional to the respective rake angle β of each cutting tool material chip.

[Brief explanation of the drawing]

Fig. 1 is a three-dimensional view of the essential part of the present invention of a band saw tooth, Fig. 2 is a side view of a circular saw tooth part, and Fig. 6 is a saw tooth with variable pitch, variable note angle and cutting tool material chips of the same thickness. FIG. 4 is a side view of a saw tooth with variable pinch, variable seat angle and equal thickness cutting tool material chips. 6.6', 6"...Cutting tool material chip t...Pitch γ...Effective rake angle (2 pieces

Claims (1)

Claims: t. A basic body, in particular made of spring steel, with a plurality of protrusions extending over the edges and each separated by a chip space, providing a seat for each cutting tool material chip and each forming the back surface of a tooth. , a plurality of cutting tool material types having a cutting edge and a rake face and provided at an effective rake angle and secured by sills and their protrusions, each two adjacent cutting tool material chips having a cutting edge or In saw teeth that form a pitch at opposing distances of the cutting edge), the cutting tool material chip (6, 65 changes pitch (1)
and a fixed saw tooth with a varying effective rake angle (γ); Sawtooth according to range 1. (1) 3. The varying pitch has individual pitches within the pitch sequence that are balanced against each other by a ratio of 1:2.5. Sawtooth as described. 4. The sawtooth according to claim 1 or 2, characterized in that positive and/or negative effective rake angles are provided in the effective rake angle thread row as effective rake angles that change. 5. When using cutting tool material chips (6, 65) constructed of the same thickness in order to vary the effective rake angle, the sheets (4) of the chips are provided with different slopes at their protrusions (3). 6. The sawtooth according to claim 4, characterized in that the number of different pitches in the pinch series matches the number of different effective rake angles in the effective rake angle series. 7. A patent characterized in that the number of different pitches in the pitch series is greater than the number of different effective rake angles in the effective rake angle series (2) to 6. The sawtooth according to claim 1 or 2. 8. Claims characterized in that the number of different pinches in the pinch series is smaller than the number of different effective rake angles in the effective rake angle series. Sawtooth according to claim 1 or 2. 9. Claims 1 to 2, characterized in that the cutting tool material chips (6, 6') are made of cemented carbide, high speed steel, ceramic cutting tool material, etc. Sawtooth according to one of the claims 1 to 9, characterized in that the cutting tool material tip (6, 6') is provided with wear-inhibiting marching. 11. A basic body, in particular made of spring steel, with a plurality of protrusions along the edge, each separated by a chip space, providing a note for each cutting tool material chip and each forming a back surface of the tooth. , a plurality of cutting tool material chips having a cutting edge and a rake face, provided at an effective rake angle, and fixed by their protrusions, each two adjacent cutting tool material chips blade or cutting edge)
A method for producing a sawtooth forming pitches at opposite distances of , in which the cutting tool material chips are fixed with a varying pitch and a varying effective rake angle, in which the basic body (1) has projections (3) made of varying pinches and varying sloped sheets (4) at their protrusions (3) and with the same or different cutting tool material chips (
6 and 65 are fixed with their sheets (4). 12. The note (4) on the protrusion (3) is produced by milling and/or grinding combined with a press upsetting process to change the effective rake angle for the cutting tool material chips (6, 6'). A sawtooth manufacturing method according to claim 11, characterized in that: 13. Cutting tool material chips (6, 6') protrude (6
12. The method for manufacturing a sawtooth according to claim 11 or 12, wherein the sawtooth is fixed with a sheet (4) of (4) and then ground. 14. The protrusions (3) of the basic body (1) are made with a regular pitch and the same slope of the sea 1-(4) and are different when using the cutting tool material chips (6, 6'). 1 of claims 1 to 9, characterized in that the cutting tool material chips (6,/l') which are followed or not identical during the grinding process carried out are fixed with a sheet (4).
The method for manufacturing saw teeth described in .